1. Field
This invention is directed to a materials dewatering and crusher unit which is particularly constructed for receiving and processing large quantities of oil refinery residues, particularly from the delayed coking process as coke feed chunks, or coal feed chunks or the like, including fines, which have been mixed with large volumes of water, whereby by the way of the present apparatus and method of operation the water is rapidly removed from the material chunks and the chunks are readily reduced to desired sizes such that the consequent substantially dried product can be conveyed readily to further processing equipment or stations by conventional conveyor systems.
As background information, the pet coke is manufactured in tall towers, approximately 30′ diameter and 100′ tall. To remove material from the towers (ovens) a hole is bored down thru in the center of the hardened coke in each tower of 18-24″ in diameter, and then a high pressure water spray blasts the broken pieces of coke from the ovens (900-1200 gpm of water at 3500 psi). Water and “Pet Coke” comes out of the tower bottom and is captured by the present unit. Our drag chain conveyor moves material and water over a deck and screens where the material is dewatered and then crushed. Additional screens are positioned preferably down stream of the crusher for additional dewatering. We run approximately 500 tons per hour of coke. The pet coke is around 55 pounds per cubic foot and crushes easily. It normally is high BTU (12000 BTU plus) and high sulfur (4 to 6 percent). Normal painted surfaces rust quickly so we are using stainless steel decks and screens and employ a galvanized frame.
Typically where delayed coking units are employed, the coke from the coking towers or drums which can hold typically 200-400 metric tons of coke can extend vertically for sixty fee or more. The coke is blasted out of the towers by high pressure water jets outletting from a hollow shaft extending down thru a large hole cut down thru the center of the solidified coke.
This pressure blasting comprises drilling a hole down thru the coke by means of a cutting device on the shaft while jetting high pressure water against the coke. This process typically takes several hours and results in many tons of cracked up coke and water being mixed in the tower. The water/coke mixture is then discharged through a bottom port of the tower to dewatering or other systems such as crushing, classifying or conveying apparatus
2. Prior Art
In such coke discharge operations, a large amount of contaminated wastewater results and must be contended with out flooding of the coking site. Many types of dewatering systems have and are being used such as shown in U.S. Patents or applications; US2003/0217960 A1; U.S. Pat. Nos. 5,460,699; 7,108,793 B2; 4,420,404; 2,474,251; 3,257,309; 5,355,696; and 4,986,910. None of the above prior apparatus or methods afford the simplicity and effectiveness of the present invention which is summarized below.